Conjunctiva

The conjunctiva is a thin, transparent mucous membrane that covers a significant part of your eye. It runs along the inside of your upper and lower eyelids and then wraps round the front of your eyeball, extending to the edge of your cornea. This structure creates a protective sac around your eye.

The conjunctiva has various functions. It contains small blood vessels that supply oxygen and nutrients, and it produces part of your tear film. It also helps to trap foreign particles such as dust or dirt, making it easier for you to blink them away or rinse them out. The tissue is normally colourless to pale pink and smooth.

As the conjunctiva is in direct contact with the outside world, it is susceptible to irritation from, for example, pollen, dust, chlorine, smoke or cosmetics. It can also become inflamed due to bacteria, viruses or allergic reactions. This inflammation is called conjunctivitis, commonly known as ‘red eye’.

The conjunctiva and contact lenses

When you wear contact lenses, the lens does not rest on the conjunctiva itself, but on the cornea and floats on your tear film. Nevertheless, the conjunctiva plays a role: it contributes to the production of the tear film and reacts to stimuli. If your conjunctiva is irritated or inflamed, wearing lenses may be uncomfortable or may sometimes be temporarily advised against by your optician or ophthalmologist.

Signs of irritation

An irritated conjunctiva may feel red, watery or, conversely, dry. You may experience itching, a burning sensation or a gritty feeling. Sometimes you may also notice a mucous discharge. These symptoms may indicate mild irritation, but could also be a sign of inflammation or an allergy. If you have any symptoms or are unsure, please have them assessed by your optician, optometrist or ophthalmologist.

Care and hygiene

As the conjunctiva comes into contact with your hands, lenses and the environment, good hygiene is important. Wash your hands before touching your eyes or lenses, and replace your lenses and lens solution in accordance with the instructions for use. This will minimise the risk of irritation or infection.